Flow control apparatus



. July 31, 1945. GOTTLIEB 2,380,836

FLOW CONTROL APPARATUS Filed April 23, 1945 5': F /6) se .55 ss a so ias I a i a0 aa e4 a r so I as iv; 45

II E WITNESSES: I INVENTOR Mnmous Go'r'n. I E B. a 7 4% BY ands,

ATTORNEY Patented July 31, 1945 um'rso sures PATENT OFFICE FLOW CONTROLAPPARATUS Manions Gottliell, Philadelphia, Pa asslgnor to WestinghouseElectric Corporation, last Pittabnrgh. Pa., a corporation ofPennsylvania Application April 23, 1043, Serial No. 484,199

3. Claims. (01. 211-122) This invention relates to, valves, moreparticularly to an arrangement oi valves for elasticiiuid-utilirlngdevices, tor example, steam or.

gas turbines, compressors, tc., and has for an .7

Conversely, an increase in output is obtained with the wideropeningoithe steam admission valve. Reductlonoi throttling losses is. usuallaccomp ed hrcl v d n flie first stage n v mmvalvesshouldbecloscdinsequencesoastoag in limit the throttling to onlythe valve'that is partially open.

Thus, it is well known in steam turbine practice to provide valvestructure wherein a plurality oi valves are open and closed successivelyto obtain better partial load eiliciency be had with a single valve, butsuch valvestruc tures have left much to be desired in the way oibalance. sealing when closed; manufacturing costs. etc.

Therefore. another object of the invention is to provide a novel valvestructure and arrangement incorporating a pr d n e a ove mentioneddesirable ieatures.

These matinee. o jects are effected by the invention as'will be apparentirom the iollowing description and claims taken in connection with theaccompanying drawing, forming a part of application. in which:

The sihsle figure is a transverse sectional view showing a valvearrangement in accordance with several groups, The to eachgroup'iscontrolled by dnefor more "steam admission valves. Variation in theturbine output isf'fobtained by openingor closing the steam admissionvalves, thus varying the number of nozzle groups in service. To securethe greatest reduction in throttling losses. the steam admission valvesshould be automatically positioned so as to allow the proper amount 0!steam to flow to carry the load. This will be accomplished by opening orclosing the steam admission valves in sequence. For example, assume thatthe turbin is provided with three steam admission valves which supplysteam to three separate nozzle groups. at the lightest loads, onLv thefirst steam admission valvewill be open or partially open and will besupplying steam to the first noilzle group. As the load on the turbinincreases, the governor will automatically open the nrst admission valveuntil it is'wide open, at" which time the throttling-losses are at aFurther increase in load will cause the governor-to automatlcallypartially open the second steam admission valve an amount depend uponthe load. However, the fl'rst steam admission valve will remain fullyopen with minlmumti'imttlingoi-the steam flow through it. Furtherincreases in load would cause tlie second valve to oper wide, at whichpointminimum throttling'is obtained before the third valve opens. withthe use of automatic multi-valves it is seen that the throttling occursonly on the valve which is partially open.

With decreasing loads the steam admission the invention.

Reie now to the drawing more in detail. 'thereis shown, at II. a turbinecomprising a rotor and a casing i2 therefor, th latter having groups oinoasles it, It and ii for admit ting suitable elastic fluid, such assteam, to the blading ll of the rotor ll.

Bteamisadmittedtothevalvecasingfl through an inlet passage II, in whichis mounted a valve cage 2! having opposed outlet ports II and ill,cooperating with valve members It and 21, respectively. iormed integralwith or rigidly mounted upon a valve stem 28.

Passage It serves to conduct steam from the outlet port 24 to the firstnozzle group II and a similar passage Ii conducts steam from the port llto the second male group II.

The valve cage 22 is formed with an extension 22' including a thirdoutlet port". with which cooperata a valve member 34, also formedintegrai with, or rigidly mounted upon, the valve stem 28. Steam passingthrough this port It is conducted to the third group oif nozzles it bythe passage 35. I

The first valve member 2' is provided with a conical suriace ll,cooperating with a sharp corner 4i, formed on the valve cage 22 at theoutlet port 14, with the result that when the valve is in closedposition a relatively tight seal is obtained at this point. Similarly,the second valve member 21 is provided with a sharp corner 4!cooperating with the conical seat 48 on the port-forming portion 25 ofthe valve cage 22, whereby tight scaling is obtained at this point also.when the valve is in closing position. It'will be noted that the secondvalve member 21 also includes a cylindrlcal piston portion 44cooperating with the cylindrical bore portion 1! of the outlet port 15.thereby providing for delayed opening of the second valve 21.

The cylindrical piston valve portion ll cooperating wlth the thirdoutlet port I! in the cage extension 22' is of such length that openingoi this port is delayed beyond the opening of the first and second valvemembers. Thus. it will be apparent that upon movement of the valvemember toward opening position. the iirst valve member 16 willimmediately open, permitting flow of steam through the passage "to thefirst nozzle group II. Continued movement of the valve stem in openingdirection will result in successive openins of the second valve memberII and the third valve member 34 for how of steam through passages Iiand II, respectively, to the second and third nozzle groups 4 and I8. rsp t vely.

It will be noted that only the first and second valve members I. and 21are provided with the mating conical surfaces and sharp cornersproviding-tight seals, inasmuch as only these two valves are subject tothe high pressures present in the inlet pamage ii. The third valvemember II is subject only to the lower pressure existing below thesecond valve member 21 when the latter is open.

The valve stem 2| is provided with an enlarged balancing piston l0 abovethe first valve member it to balance the forces exerted against theunder surface of the lowest or thirdvalve member 8!.

To provide equalized pressures against these two piston surfaces. thereis formed a pressure balance passage Ii, extending from end to end oithe valve member. a

The valve member is operated in the usual manner. it having an extensionor rod 51 projecting upwardly beyond the casing II and received betweenthe ears II of the bifurcated lever It. the latter being operated,through linkage j. by suitable governor mechanism (not shown); Acompression spring I. confined between shoulder l1 formed integral with.or secured rigidly to. the valverod llandtheupperendoithebushing It.serves to urge the valve rod upwardly for valve -s,seo,ese

opening when such movement is permitted by the corresponding movement oithe bifurcated end of the lever ll. Downward movement of the bifurcatedend forces the valve rod downwardly to eii'ect valve closing. I While,for the sake o! simplicity and clearness, the invention has beenillustrated as involving only three valve members and passages. it willbe obvious that additional valve members and passages could be providedwithout departing from the spirit of the present invention.

While the invention has been shown in but one iorm, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various changes and modifications without departing fromthe spirit thereof, and it is desired, therefore, that only suchlimitations shall be placed thereupon as are specifically set forth inthe appended claims.

What is claimed is:

1. Valve mechanism comprising a valve housing having an inletpassageincluding first and second outlets; means providing a firstdischarge passage irom said first outlet; means providing a seconddischarge passage from the second outlet. said second discharge passagehaving a branch outlet; means providing a third discharge passage fromsaid branch outlet; and a unitary valve structure movable between firstand second limits for simultaneously controlling flow through saidoutlets, said valve structure comprising a stem and first, second andthird valve members carried thereby and so spaced therealong that at onelimit of movement of the stem they close the first, second and branchoutlets, respectively, and when moved from said one limit to the otherlimit they successively open the three outlets.

2. Structure as specified in claim 1. wherein the first valve member isof the poppet type and the second valve member is a combination ofpoppet type and cylinder type, whereby the outlets from the inletpassage may be sealed bottle-tight.

3. Structure as specified in claim 1, wherein the first valve member isof the poppet type, the third valve member is of the cylinder type andthe second valve member is a combination oi poppet and cylinder types.

MANIOUB GO'I'I'LJEB.

